Coverage for gpaw/tddft/units.py: 100%

1# https://www.answers.com/topic/hartree-units 

2 

3from math import pi 

4 

5from ase.units import _hbar, _eps0, _me, _e, _c, Bohr, Hartree, s 

6 

7_a0 = Bohr * 1e-10 

8_autime = _hbar**3 * (4 * pi * _eps0)**2 / (_me * _e**4 

9 ) # 1 autime ~ 2.42e-17 s 

10 

11# Conversion factors between ASE and GPAW units 

12 

13attosec_to_autime = 1e-18 / _autime # 1 as ~ 0.0413 autime 

14autime_to_attosec = _autime * 1e18 # 1 autime ~ 24.2 as 

15 

16# ASE time unit is [Å sqrt(u/eV)] 

17# Hartree time unit is [hbar/Hartree] 

18asetime_to_autime = 1 / s / _autime # 1 ASE time unit ~ 420.9 autime 

19autime_to_asetime = 1 / asetime_to_autime 

20 

21eV_to_hartree = 1.0 / Hartree # 1 eV ~ 0.0368 Eh 

22hartree_to_eV = Hartree # 1 Eh ~ 27.2 eV 

23 

24hartree_to_aufrequency = 1.0 # Eh ~ autime^(-1) since hbar=1 

25aufrequency_to_hartree = 1.0 # autime^(-1) ~ Eh since hbar=1 

26 

27eV_to_aufrequency = 1.0 / Hartree # 1 eV ~ 0.0368 autime^(-1) 

28aufrequency_to_eV = Hartree # 1 autime^(-1) ~ 27.2 eV 

29 

30eA_to_audipolemoment = 1 / Bohr # 1 eÅ ~ 1.8897 aulength^(-1) 

31audipolemoment_to_eA = 1 / eA_to_audipolemoment 

32 

33assert eV_to_aufrequency == eV_to_hartree * hartree_to_aufrequency 

34assert aufrequency_to_eV == aufrequency_to_hartree * hartree_to_eV 

35 

36# Short-hand names 

37eV_to_au = eV_to_aufrequency 

38au_to_eV = aufrequency_to_eV 

39as_to_au = attosec_to_autime 

40au_to_as = autime_to_attosec 

41au_to_fs = au_to_as / 1e3 

42fs_to_au = as_to_au * 1e3 

43eA_to_au = eA_to_audipolemoment 

44au_to_eA = audipolemoment_to_eA 

45 

46# Rotatory strength 

47# See https://doi.org/10.1016/0009-2614(95)01036-9 

48rot_au_to_SI = _e**2 * _hbar / _me * _a0 # 1 au = 1.6e-52 J C m / T 

49rot_au_to_cgs = rot_au_to_SI / (1e-6 / _c) # 1 au = 4.7e-38 erg esu cm / gauss